Research On Temperature Identification And Overheating Protection Of Submersible Motor Based On Manifold

This subject is in the background of safe and stable operation, energy-savingand consumption-reducing of each oil of our country, researching on temperatureidentification of the motor. In order to solve higher energy consumed, hightemperature over-voltage fault and field monitoring inconvenience, scientificquestions to be solved in this field is researched on. Theory research foundation isprovided for the efficiency and security operation of the ESM(electrical submersiblemotor). Mainly contents of this paper are as follows:In view of the influence of the motor’s current and speed on the temperature,the plan based on adjusting power frequency to realize overheating protection ofmotor is determined. Temperature field model of ESM is set up, manifold analysismethod is applied on temperature field model of ESM, the meaning of relatedparameters in the model and the relationship between the parameters is analyzed.The stator temperature manifold expression is got through the analysis of internalheat transfer of ESM. Based on the rotor slot harmonic theory, FFT algorithm isused to extract rotor slot harmonic from the stator current spectrum for motorsensorless speed identification.Concerned parameters of temperature field model are analyzed by usingMATLAB, the parameters on the influence of the temperature of the motor is got bysimulation. The sensitivity of the relation between the temperature and statorthermal resistanceRs, rotor thermal resistanceRr, and coupling thermal resistanceRm is analysed, the stator thermal resistanceRs is found to be closely related tothe motor’s cooling capability. On the basis of initialization of the parameters oftemperature field model, iterative computation forRs is Determined. Therelationship between the temperature of the motor and the frequency simulation issimulated, the conclusion that the temperature will reduce by reducing thefrequency, which proves the overheating protection system for ESM is feasible.Data acquisition platform is set up based on industrial PC, motor speed isidentified under different frequencies. Based on the temperature field model, two-dimensional manifold of ESM stator temperature is identified under the condition of the stator thermal resistance feedback. The comparision between estimatedtemperature from the temperature field model and the true temperature of the motorverifies the validity and feasibility of the scheme.Control system is set up based on DSP2812. Based on the temperature fieldmodel, the temperature identification of the motor and overheating protection arerealized.